Document 1 (WO 2013/172034 A1) discloses a multiple glass pane. The multiple glass pane disclosed in Document 1 has a reduced pressure space formed between a pair of glass plates.
The reduced pressure space is made by evacuating a space between the pair of glass plates with a vacuum pump. To evacuate the space between the pair of glass plates with the vacuum pump, it is necessary to form an outlet in one of the pair of glass panels in advance and connect the outlet to an inlet of the vacuum pump with an evacuation pipe.
In Document 1, subsequent to the evacuation the space is divided by a region forming member placed inside the space to form a partial region not including the outlet. After that, the pair of glass plates are cut to separate the partial region. As a result, a multiple glass pane devoid of an outlet and an evacuation pipe can be produced.
According to Document 1, heating the region forming member is necessary to form the partial region. However, heating the region forming member may result in emission of gas from the region forming member. After formation of the partial region, it is very difficult to improve the degree of vacuum of the partial region by use of the vacuum pump and therefore the degree of vacuum of the partial region is likely to become worse due to emission of gas from the region forming member. Hence, in some cases multiple glass panes may fail to have desired thermal insulating properties.